Pygmy Halfbeak (Dermogenys collettei)

Pygmy Halfbeak (Dermogenys collettei)

A Pygmy Halfbeak found resting among a pile of leaf litter in a freshwater forest stream.

Family: Zenarchopteridae

Species Name: Dermogenys collettei
Common Name: Pygmy Halfbeak, Sunda Pygmy Halfbeak
Presence in Singapore: Native
Habitat: Freshwater and mangrove streams, catchments and more
Conservation Status: Least Concern (Red Data Book 3)

A common and adaptive species, the Pygmy Halfbeak can be found in freshwater to brackish streams such as in forests and mangrove swamps. It is a close relative of the popular Wrestling Halfbeak (Dermogenys pusilla), that have similar habits as well. It grows up to 7cm but are usually found smaller than that, giving it the common name especially when compared to its relatives. 

An accurate way to tell it apart from the other freshwater halfbeak in Singapore, the Forest Halfbeak (Hemirhamphodon pogonognathus), is that its dorsal fin starts behind the origin of the anal fin. It feeds on passing prey such as fallen insects at the surface like all halfbeaks. Being in the family Zenarchopteridae (Viviparous Halfbeaks) alongside the Forest Halfbeak, the Pygmy Halfbeak practices internal fertilization and give birth to live young.

A Pygmy Halfbeak found foraging in a mangrove swamp during a rising tide (Photograph by: Lumin Ong).

References

• Lim, K.P. and Ng, K.L. 1990. A Guide to the Freshwater Fishes of Singapore. Singapore Science Centre.
• National Parks Board (NParks). Freshwater Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/freshwater-fishes.